The Craigslist murderer, who says she notched up victims on the handle of her favourite knife, begs to be spared lethal injection

Teenage satanist serial killer Miranda Barbour has notched up as many as 100 victims, but says she should be spared the death penalty because it is too "inhumane".

The 19-year-old Craigslist murderer – who admits wiping out between 22 and 100 victims over six years – is now begging to be spared lethal injection because she says execution is a “cruel and inhumane punishment”.

He lawyers have filed papers saying: “The criminal justice system is fallible... subjecting inappropriate persons to the death penalty”.

But police have not said whether they have found the knife, which would confirm her story.

Newlywed Barbour, who is being compared to the serial killer in TV show Dexter because she claims she only killed “bad people,” confessed to the staggering death toll when she was pressed for her total number of victims.

In a prison cell confession, Barbour, arrested along with her husband, said she adopted a murderous alter ego called Super Miranda whenever she committed one of her thrill killings.

As the Mirror revealed, Barbour claimed she joined a satanic cult aged just 13 in the town of North Pole, Alaska, and spent her teenage years on a nationwide murder spree.

Investigators believe she had encounters with at least 30 men she met via the internet after offering herself as a “companion”.

She and husband, Elytte Barbour, 22, face several charges including murder. Both have pleaded not guilty.

The Barbours are accused of luring Troy LaFerrara, 42, through an internet Craigslist ad and stabbing and strangling him to death on November 11, 2013 in Sunbury, Pennsylvania. If convicted in that state, both would face lethal injection.

The couple, married for only three weeks at the time of the slaying, just wanted to kill for fun, police said.

Elytte Barbour told police at the time that he and his wife had tried to kill others, but the plans didn’t work out.

But in an interview she said: “When I hit 22, I stopped counting. I can pinpoint on a map where you can find them.”

Investigators are now pouring over her sordid internet encounters that Barbour and her husband organised for cash in the months prior to her arrest while they lived in Dunn, North Carolina.

He said his wife regularly hired herself out as a ‘companion’ from £30 to £600 an hour to men she met on various meet-up websites.

He said he did not mind this because there was no sexual contact between his wife and her clients.

He said at the time: “She is not a prostitute.

“What she does is meet men who have broken marriages or have no one in their lives, and she meets with them and has delightful conversation."

According to her prison interview, she joined the satanic sect as a young girl in the town, which is in the Fairbanks North Star Borough of Alaska and has a population of 2,210.

Claiming to have been sexually abused at the age of four, Barbour said that she only killed "bad people" and was brought up in the cult by a man she would not identify.